Heat transfer bearing mounting

ABSTRACT

An antifriction bearing assembly mounting wherein the inner ring of the bearing, in the preferred embodiment, is mounted on a hollow sleeve which in turn is mounted on the rotating shaft, the sleeve extends axially along the shaft and is hollow in the manner of an envelope. The interior is filled with a heat conductive material such as sodium and the axial end of the sleeve remote from the bearing has radially outwardly directed cooling fins associated therewith. In this manner, heat created during rotation of the bearing assembly is drawn away from the inner ring of the bearing to a point where it can be effectively dissipated.

United States Patent Irwin Feb. 29, .1972

[54] HEAT TRANSFER BEARING FOREIGN PATENTS 0R APPLICATIONS MOUNTING 115,751 1/1946 Sweden ..30s/77 [72] Inventor: Arthur S. Irwin, Bemus Point, NY.

Primary Examiner-Edgar W. Geoghegan [73] Asslgneez TRW Inc., Cleveland, OhIO Assistant Examine, Frank Susko [22] Filed: Oct 13 1969 Attorney-Hill, Sherman, Meroni, Gross & Simpson [21] App1.No.: 865,605 [57] 7 ABSTRACT An antifriction bearing assembly mounting wherein the inner [52] us. CI 308/189 ring of the bearing, in he pr f rred m en i m e [51] Int. Cl. ..Fl6c 37/00 On a hollow Sleeve which in turn is mounted on the rotating 581 Field of Search ..308/76, 77, 184, I89 shaft. the sleeve extends axially along the shaft and is hollow in the manner of an envelope. The interior is filled with a heat [56] m- Cited conductive material such as sodium and the axial end of the sleeve remote from the bearing has radially outwardly UNITED STATES PATENTS directed cooling fins associated therewith. In this manner, heat created during rotation of the bearing assembly is drawn 3,404,925 10/1968 Bailey ..308/ l 84 away from the inner ring of the bearing to a point where it can 413,925 10/1889 Blanchard. be ff y i ip 2,330,121 9/1943 I-Iemtz ...308/77 2,352,206 6/1944 Kendall ..308/77 5 Claims, 3 Drawing Figures HEAT TRANSFER BEARING MOUNTING BACKGROUND OF THE INVENTION being used. in higher speed applications. Although the friction crated during operation of such an assembly per rotation may.v

besmall, due to the high-speed operation thereof, frictional heat can quickly build to a point where it will reduce the effective life of the assembly. Many systems have been devised for reducing or dissipating this heat. The most commonly used systems'to date have been air or lubricant flow systems which attempt to remove the heat by circulating a flow of oil, air or other coolant, through .the rotating bearing assembly. As speeds and loads .of such assemblies increase, it becomes increasingly difficult to cool the bearing assembly by subjecting it to such a flow. Further, in many instances bearing assemblies are usedadjacent a seal which is designed to prevent a flow in the axial direction, thereby interfering with the ability.

to cool the assembly.

Many attempts have been made to reduce the. heat by providing a coolant flow through the housing in-which the assembly is received. However, of the net heat generated inan.

antifriction bearing, more heat flows to the innerrace ring thanflows-to the outer. Further, preferential removal of heat through the housing or outer member of the bearing system creates differencesin thermal expansion which disturb the bearinggeometrical parameters, for example, the dimensional clearancesv Removal of heat from the inner race ring is complicated: by the fact that the race must rotate. with the shaft which it supports.

SUMMARY OF THE INVENTION In order .to overcome these deficiencies of the prior .a.rt,,my invention provides, in.a preferred embodiment, a shaft-carried hollow envelope member on which the inner race ring of the bearing assembly is mounted. The envelope is filled with a coolant, such as sodium, which has a high thermal conductivity. The'envelope extendsaxially along the shaft to a point, generally exterior of the housing, where radial clearance is sufiiciently large. to accommodate radially extending cooling fins for dissipation of the heat carried by the coolant. In order to increase the effectiveness of the heat removal, the coolant is preferable entrapped in a thin-walled envelope. The walls are kept thick enough to provide dimensional stability during operation, but thin enough to allow good thermal conductivity. To further enhance the cooling capacity of the device, the heat radiating fins may be subjected to a coolant bath of oil, water, air or the like.

In analternative embodiment, the inner race of the antifriction bearing assembly may be formed as a portion of the outer diameter of the coolant filled envelope. Additionally, in yet another embodiment, the inner or outer raceways or both may behollow andfilled with the coolant with radiating fins, if desired, extending axially or radially.

lt is therefore an object of this invention to provide an increased cooling capacity bearing mounting.

It is another object of this invention to provide a mounting for antifriction bearings consisting of a shaft-carried hollow It is a general object of this invention to provide an antifriction bearing assembly for'high-speedshaft mountings which utilizes a hollow member filled with a high thermal conductivity coolant to dissipate operating heat from the" antifriction bearing.

BRIEF DESCRIPTION OF THE'DRAWINGS tion bearing assembly received in a housing and associated witha shaft encompassing heat transfer mounting member.

FIG. 2 is a cross-sectional fragmentary view similar to FIG.

-1 illustrating a different embodiment of the heat transfer mounting wherein the mounting serves as the inner race ring.

FIG. 3 is a fragmentary cross-sectional view of yet another embodiment of the antifriction bearingassemblyhaving hollow inner and outer raceways filled with heattransfer coolant and'having axially projecting, radiating fins.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates an,antifriction ball bearing assembly 10 received in a housing II. The antifriction assembly 10 consists of a outer race ring l2, a concentric inner racering l3, and a series of antifriction rolling elements 14 interposed therebetween.-A coaxial heat transfer mounting member 15 is disposed radially inwardly of the inner race ring 13.

The mounting member 15 is designed to encircle a shaft (not shown) which is rotatable with respect to the housing 11 and which is retained in position through the bearing assembly l0.-The mounting member 15 is utilized to effectuate dissipation of operation caused heat from the inner race ring .13 of the assembly.

The member 15 is affixedto the shaft, eitherby-a press-fit relationship or byibrazing or other fastening methods, and rotates therewith. The member 15 is axially elongated and has oneend. 17 adjacent the bearing assembly and its other end 18 spaced therefroma desired distancealong the shaft. The inner diameter-19 rides on theshaft while the outerdiameter 20 is configured as at 21,to receive the inner race 13 of the bearing assembly.

In:the embodiment illustrated in FIG. 1, the inner raceway 13 of the bearing assembly is entrapped between a shoulder 22 on the outer diameter 20 and a retaining nut 23, threaded onto the end 17.

The member 15 is constructed in the manner of an envelope with inner, 24 and outer 25 spaced-apart axially extending walls closed by-end walls 26 and 27 at the axial ends 17 and l8. The hollowcircumferential cavity 29 between the inner and outer walls,24, and 25 is filled with high thermal conductivity coolant 30 such as sodium. Although sodium is described as a preferred coolant, it is to be understoodthatany liquid or liquefiable high thermal conductivity coolant maybe used.

The outer wall 25 of themember 15 is maintained as thin as possible with due regard to operational stability and radial load pressures. Where-necessary,-the end-17 of the member 15 which receives the inner race ring may be constructed thicker distance suffic'ient to place the cooling fins 35 at a point; with respect to the. bearing assembly. 13, where there is sufiicient space for theheatto be radiated from the fins. Radiation -of heat may be=aided bywthe provision of an soil; air; water or other coolant'bath'.

Due to the thermal conductivity of the coolant 30, it can be seen that heat will be drawn from the inner race ring 13 of the bearing assembly through the thin outer wall 25 of the member 15 and then to the cooler end 17 of the member where it will be dissipated through the fins 35. in this manner, the bearing assembly may be kept relatively cool during operation. Of importance here is the fact that my invention does not interfere withthe use of normal lubricating and/or cooling systems in connection with the bearing assembly 10, but may be used to complement such systems. Further, my invention does not rely upon any moving members or complicated mechanical structures.

F IG. 2 illustrates a modification 40 of the member 15 which has the outer wall 25a contoured with a circumferential groove 41 adjacent the end 17a. The groove 41 provides the inner raceway for the bearing assembly 10a. ln this manner, heat dissipation through the wall 25a may be enhanced while at the same time providing a semiyielding inner raceway if desired. The member 40 acts to dissipate heat in substantially the same manner as the member 15.

FIG. 3 illustrates a further modification of my device which may be advantageously used in connection with a bearing sup port positioned at the end of a shaft or adjacent the exterior of a housing. The figure fragmentarily illustrates the end of a housing 50 which receives the outer race ring 51 of an antifriction bearing assembly 52. The assembly 52 supports a shaft 53 which is in contact with the inner race ring 54. Because the bearing assembly 52 is located at the end 55 of the housing 50, it may project axially therebeyond.

The shaft 53 is indicated as terminating at 56 at approximately the point of termination of the housing. It is, however, to be understood that the shaft may extend beyond the housing and that the housing may be in the form of a pillow block supporting the midpoint of a long shaft.

Both the inner and outer race rings 54 and 51 are hollow and are filled with a high thermal conductivity coolant 60 such as sodium. On the axial end 61 of the race ring which projects beyond the housing, a series of axially extending cooling fins 63 is provided for the dissipation of heat. As in prior embodiments, the thermal conductivity of the coolant 60 will aid in heat transference from the running faces of the bearing assembly to the area of the fins where it may be readily dissipated.

Although the fins illustrated in FIG. 3 are shown as projecting axially, it is to be understood that they may also project radially. For example, the fin 63a may be an axial extension from which radial fins may project outwardly. Alternatively, the fins 63b may be axial projections from which further coolant fins could project radially inwardly.

It can therefore be seen from the above that my invention provides for a bearing assembly memberwhich is hollow and filled with a high thermal conductivity coolant to transfer the heat generated during operation of the bearing assembly from the rolling elements and raceways of the assembly to a point, spaced from the assembly, where the heat can more readily be dissipated.

Although the teachings of may invention have herein been discussed with reference to specific theories and embodiments, it is to be understood that these are by way of illustration only and that others may wish to utilize my invention in different designs or applications.

I claim as my invention: t

1. A mounting member for an antifriction bearing assembly, the assembly having an inner race portion encircling and rotating with a shaft, the member comprising: a heat transfer device having an inner diameterring wall, an outer diameter ring wall, said walls spaced radially from one another, said -walls connected at their axial ends enclosing a .ring-shaped space between the said walls, said space substantially filled with a high thermal conductivity coolant, said device axially elongated, the inner diameter wall dimensioned to be received around a shaft in circumferential engagement therewith for rotation therewith, the inner race portion of the bearing assembly in circumferential contact with theouter diameter wall ad acent one axial end of said wall, and heat exchanger means on said device axially spaced from the one axial end, said coolant drawing heat from the asmmbly adjacent the one axial end and said means drawing heat from the device adjacent the heat exchanger means whereby heat will be drawn from the area of the bearing assembly and dissipated from the device at a point from the bearing assembly.

2. The member of claim 1 wherein a second axial end portion of the said heat transfer member remote from the said one axial end has a plurality of heat dissipating fins projecting radially outwardly therefrom, said fins constituting the said means.

3. The member of claim 1 wherein the heat transfer member is relatively thin-walled and is hollow in the manner of an envelope having inner and outer spaced-apart axially extending circumferential walls closed at the axial ends, the heat transfer member fitting on the shaft ,in the manner of a sleeve and being effective to cool the shaft through heat dissipation to the interior of the envelope.

4. The member of claim 1 wherein a portion of the outer diameter wall adjacent to said one axial end is configured to provide the inner race of the bearing assembly, the said outer diameter wall including a circumferential race therearound.

5. The member of claim 1 wherein the said heat transfer member has an exterior configuration adjacent to the said one axial end for unclampably receiving a separate inner race ring of the bearing assembly, the separate race ring having an inner diameter in circumferential engagement with the outer diameter wall. 

1. A mounting member for an antifriction bearing assembly, the assembly having an inner race portion encircling and rotating with a shaft, the member comprising: a heat transfer device having an inner diameter ring wall, an outer diameter ring wall, said walls spaced radially from one another, said walls connected at their axial ends enclosing a ring-shaped space between the said walls, said space substantially filled with a high thermal conductivity coolant, said device axially elongated, the inner diameter wall dimensioned to be received around a shaft in circumferential engagement therewith for rotation therewith, the inner race portion of the bearing assembly in circumferential contact with the outer diameter wall adjacent one axial end of said wall, and heat exchanger means on said device axially spaced from the one axial end, said coolant drawing heat from the assembly adjacent the one axial end and said means drawing heat from the device adjacent the heat exchanger means whereby heat will be drawn from the area of the bearing assembly and dissipated from the device at a point from the bearing assembly.
 2. The member of claim 1 wherein a second axial end portion of the said heat transfer member remote from the said one axial end has a plurality of heat dissipating fins projecting radially outwardly therefrom, said fins constituting the said means.
 3. The member of claim 1 wherein the heat transfer member is relatively thin-walled and is hollow in the manner of an envelope having inner and outer spaced-apart axially extending circumferential walls closed at the axial ends, the heat transfer member fitting on the shaft in the manner of a sleeve and being effective to cool the shaft through heat dissipation to the interior of the envelope.
 4. The member of claim 1 wherein a portion of the outer diameter wall adjacent to said one axial end is configured to provide the inner race of the bearing assembly, the said outer diameter wall including a circumferential race therearound.
 5. The member of claim 1 wherein the said heat transfer member has an exterior configuration adjacent to the said one axial end for unclampably receiving a separate inner race ring of the bearing assembly, the separate race ring having an inner diameter in circumferential engagement with the outer diameter wall. 